The present invention pertains generally to handheld devices capable of discharging fluids, singly or combined, through a detachable tip.
In wide use for many years in the dental profession are handheld devices for discharging pressurized air and water flows into the mouth. Such devices typically include concentric conduits, termed a tip, for water and air flows with the conduits terminating at a discharge point remote from a handle of the device. Such tips are detachable as they must be sterilized prior to use with a new patient. Accordingly, several times a day, a dentist or technician must change the syringe tip and over the course of the day, considerable effort is expended in tip removal and replacement as types of dental syringes often utilize threaded components to secure syringe tip in place in the syringe head. Commonly, a tool is required for tip removal for the backing off of a nut element and subsequent proper tightening of same which are repeated several times during the course of a day.
Another consideration that must be given to securing a syringe tip in place in the syringe head is the prevention of accidental tip ejection during syring use. As pressurized air and water flows are applied to the rearward end of the syringe tip, it is important that the connection between the tip and the syringe head be a positive one to avert the risk of tip loss. Further, it is desirable that tip securement be achieved without reliance on resilient components susceptible to deterioration or wear. Examples of dental syringes utilizing threaded collet elements for tip attachment are found in U.S. Pat. Nos. 4,957,483, 4,248,589 and 4,026,025 to mention a few. U.S. Pat. No. 4,975,054 utilizes a spring clip for tip retention.